One of the worst features of the Chinese system of religious persecution is that it gives money as a reward for delation. This creates a widespread culture of generalized suspect. Your neighbor may be your enemy, not even because he or she disagrees with your religion but because the rewards may offer a welcome supplement to a meager monthly income.
In the early morning, many Chinese perform physical exercises. Notwithstanding the surveillance, some of them may still be Falun Gong practitioners, and sometimes they may give leaflets to those exercising with them, or leave them around to be found by the morning gymnasts.
Now, there is a risk that these leaflets may become a precious catch for the bounty hunters eager to denounce Falun Gong practitioners for a fee.